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I have a FAA Private VFR SE license based on my foreign license, and added IFR in my home country; how to upgrade the FAA license?
I already validated my non-US licence and got a FAA Private VFR SE Licence based on my foreign licence. I recently completed my IFR rating in my home country and was wondering how to 'upgrade' my FAA licence and add the IFR privileges?!
I tried my best to find something on google but I only found references to a "FAA Instrument Knowledge Test Foreign Pilots" without any details.
Any experience or pointers for me?

I recently completed my IFR rating in my home country Which country may I ask?

I assume that your FAA private license was issued under 14 CFR 61.75, and that section also includes the requirements for adding instrument privileges:

(d) Instrument ratings issued. A person who holds an instrument rating
  on the foreign pilot license issued by a contracting State to the
  Convention on International Civil Aviation may be issued an instrument
  rating on a U.S. pilot certificate provided:
(1) The person's foreign pilot license authorizes instrument
  privileges;
(2) Within 24 months preceding the month in which the person applies
  for the instrument rating, the person passes the appropriate knowledge
  test; and
(3) The person is able to read, speak, write, and understand the
  English language. If the applicant is unable to meet one of these
  requirements due to medical reasons, then the Administrator may place
  such operating limitations on that applicant's pilot certificate as
  are necessary for the safe operation of the aircraft.

The "appropriate knowledge test" in this case is the Instrument Rating - Foreign Pilot test, it's described here with a few sample questions. Some more information is here, including the point that you don't need any prior authorization to take the test:

• Requires NO instructor endorsement or other form of written
  authorization.

I'm not sure about the exact process involved (I guess you just do the test and send the certificate to the FAA) but the FSDO that validated your foreign license for VFR should be able to give you all the details.

thanks for your answer. I will contact the respective FSDO and will ask them for the correct procedure.

@alex25 If you get any extra information from the FSDO that would be helpful then you can edit my answer, or even add a new answer yourself. Both are perfectly acceptable here.

We deal with a lot of foreign pilots and certification issues, just remember that any time you do anything that changes your FAA certificate based on a foreign certificate (add anything) you must complete the entire verification process again!

I just contacted FSDO about adding the IFR rating to my FAA PPL land, multiengine,based on my foreign license, and the answer was I need to go through the verification process again, then take the test and then create an application with IACRA, after that call the fsdo to get an appointment.


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Can fighter aircraft glide?
In case of engine failure, do the fighter jets have such a stable airframe so that they can glide their way through to the nearest landing strip (As it happened in the case of Gimli glider)?

They are more likely to point it at an empty field and ejecting. Safer for all involved.

I'm pretty sure there are accounts of dead-stick fighter landings, I saw a cockpit recording of one on youtube a while ago

F16 dead-stick landing

There is and event of fighter aircraft gliding and lading safely http://en.wikipedia.org/wiki/Cornfield_Bomber

@jnovacho that was after eject and engine on idle (with will still provide thrust)

The F-16 has a glide ratio of 7nm per 5000ft AGL (about almost 6:1) this means that with no engine power it can travel 6 (5.83333333) nautical miles for every 6,000ft (a nm) it has in altitude at best glide speed.

Technically, all stable winged aircraft can glide not all airplanes as suggested by many below, for example the eurofighter (aka typhoon) was deliberately designed to be unstable requiring computers to keep it in the air to allow for more extreme behaviour whilst flying. I write this on the understanding that by "glide" you mean something like "gracefully land with no engine power" type of flying as opposed to "falling in a flat spin" which technically could be seen by some as gliding, in which case even the typhoon could "glide".

@Wardy just because the engine is out doesn't mean the computer and the hydraulics don't work. I don't know about the Typhoon, but most aircraft that need them (as has been mentioned in the answers below) have backup systems to allow it to be controllable (thus able to glide to a safe landing) even without engine power, and even if it's aerodynamically unstable.

If a person without a parachute can glide to particular target location, so can a fighter jet. It's just a function of altitude and distance.

@falstro as I stated above the typhoon is deliberately designed so that it wont fly unless constant adjustments are made to flaps, without power those adjustments cannot be made thus it's logical to assume that gliding could be an issue. A human without the 6 computer systems support cannot fly a typhoon ... http://www.defence-suppliers.com/supplier/Eurofighter_Typhoon/

@Wardy and so is pretty much any modern fighter, including the F16, yet it can glide because it has backup systems (like a RAT or EPU) to power computers and hydraulics when the engine fails. I don't know if the Typhoon has such systems, but most aircraft do.

@falstro: The F16 is not designed unstable, unlike the Eurofighter or the F22. Even the more modern F18 is stable (stable here means CG ahead of neutral point)

@slebetman actually, the f16 is the first aircraft deliberately designed to be aerodynamically unstable

All airplanes can glide, if they couldn't they wouldn't be able to fly in the first place. When you glide an aircraft you are converting height into airspeed, which you can use to move across the ground. How far you can go across the ground for height lost is called the glide ratio for the aircraft. Gliders have a very high glide ratio as their wings are designed to provide lots of lift at low speeds, fighters have a very low glide ratio as they are designed to provide lift at a much higher speed enabling the fighter to achieve high airspeeds efficiently.
So a fighter will glide, it just won't be able to glide that far over the ground. If a fighter has enough altitude to trade for speed and a strip close enough by it can be done (and has been done in the past) by a skilled pilot.

OK, all Airplanes then.

The question was about fighters, and I've get to see a fighter balloon...

@Articuno but, but, balloons can glide, in fact they are very good at it. :p

@Articuno I'm pretty sure the only aircraft that can't glide are rockets and various projectiles, as for the rest of them (including balloons), they all glide pretty well.

@Articuno Wait wait, how does a helicopter glide?

@CaptainCodeman: Autogyration?

@keshlam Holy crap I didn't know such a thing existed, thanks for that!

This is not correct.  Modern fighters eg. the Typhoon, F22, etc. are designed to be aerodynamically unstable.  Without computer assisted corrections to their control surfaces they can not stay in the air.

@JamesRyan, if I understand correctly, gliding means flight without propulsion (as in the case of the Gimli Glider that the asker gives as an example). If we took it to mean the absence of any power, it wouldn't be feasible with anything but mechanically actuated control surfaces.

@JamesRyan just because it's aerodynamically unstable doesn't mean it can't glide and will go straight down the moment the engines cut out. It will still glide. Without electrical power to control the aircraft it may not be able to glide as far as otherwise (the aircraft may intent to pitch down or up more than optimal for example) but it will still cover distance over ground, trading speed for altitude until speed drops to below stall speed for the attitude it is at at that critical moment.

Speaking of the Gimli Glider, Boeings have a ram air turbine (I think that's the term) that drops down from the belly to provide some hydraulic pressure in case of total engine failure. Does anyone else do this, such as Sully's A320? Any fighters or bombers? Is it fully automatic or does the pilot have to deploy it?

@Most commercial and military jets have a RAT, including Airbus aircraft. These usually deploy automatically. Some advanced military aircraft use chemical based reserve power systems, for instance the F22, I expect it is to limit the number of doors that need to open.

"The question was about fighters, and I've get to see a fighter balloon".  There were lots of them in WWI

I argue balloons were more bombers than fighters.. ;)

I've never heard of a drifting balloon being used for anything but (possibly) recon. Powered lighter-than-air craft have certainly been used or tried as bombers (WWI Zeppelins), aircraft carriers, and possibly as AA batteries. Tethered balloons have long been used (since US Civil War) for observation and for interfering with aircraft (barrage balloons). Observers on them could have carried small arms to discourage enemy fighters from bothering them.

"All aircraft can glide" reminds me of Maxim 11 -- "Everything is air-droppable at least once."

@jwenting an aerodynamically unstable aircraft will only glide as long as there is power to the FCS and surfaces. There will be batteries and hydraulic accumulators to provide temporary control in the event of an engine failure. However when either is depleted then an unstable aircraft will depart if there is no mechanical control, it will not glide irrespective of altitude. A pilot may just  about be able to control a mildly unstable aircraft but only if he has a mechanical backup.

@PhilPerry Japan used drifting balloons with bombs attached in WWII. They released them into the jet stream (unpiloted) and just let them drift over to the U.S. This wasn't particularly effective, though, given the complete lack of guidance. Most of them just hit in the middle of nowhere.

All airplanes can glide. Some glide better than others.
A very old reference I read talked about engine-out landings in military aircraft. Their procedure was arrive at the airfield at X feet, circle once and land. Trainers like the T-33 needed 2,500 feet, other aircraft needed 3,500-5,000 feet.
An F-104, which is basically an engine with fins, needed 20,000 feet for the landing loop. So unless you have a flameout in the stratosphere (or directly overtop an airport) you would simply point it at an empty space on the ground and eject.

I was thinking to the f104 when reading the question :) thank you for that information.

And yet successful dead stick landings were made in the F-104. For example, see http://en.wikipedia.org/wiki/Lockheed_XF-104#Testing_and_evaluation.

Yes, all aircraft have a glide ratio.  On many of the higher-performance fighters, it's 1:1 at best (1 foot altitude traded for one foot forward gliding).
Many of the newer fighter aircraft are intentionally unstable.  They aren't really flown by the pilot; they're flown by a Flight Control Computer System (FLCCS) which depends on electrical and hydraulic power; the pilot tells the FLCCS what they want to do and the FLCCS uses electrical signals and hydraulics to move the flight controls.  Electricity and hydraulic power are provided by generators and pumps on a gearbox driven by the engine.  Ergo, engine-out (especially on a single-engine bird) means they can lose the FLCCS which means they are, effectively, giant "lawn darts."
I spent multiple years as a Crew Chief on F-16's with Uncle Sam's Air Force.  As a single-engine plane, we jokingly said that, when the engine went out, it was in "lawn dart mode."
The F-16 does have backup systems.  The aircraft battery will supply power for a couple minutes, depending on what all you're using.  The hydraulic accumulators will provide hydraulic power for a minute or two, assuming you don't get too crazy.  And the Emergency Power Unit (a small, monopropellant turbine in the right strake of the aircraft) will start promptly after losing the engine, providing electricity and hydraulic power for several minutes as necessary (the battery and accumulators keep you under control while it spins up).  Ergo, if you lose the engine, you lose propulsion but you still have electricity and hydraulic power.  So you can still maintain control of the airplane.
We had more than one occasion, in my time, where we had an F-16 engine conk out (we were playing with brand spankin' new Block 50s with a new model of engine) and the pilot managed to glide the plane in without injury or damage to the aircraft.  They were near the base when it happened, the EPU fired (so they were able to maintain control of the aircraft), the glide ratio was sufficient to reach the runway and the tailhook (yes, Air Force birds have 'em) caught the cable and stopped them safely.
So, the short answer is yes, modern fighter planes can glide.  Different planes have different ratios, some of them little better than a rock thrown at altitude.  And, even if they're designed to be inherently unstable, they have backup systems such that the pilot can maintain control in an engine-out situation.

I don't believe you glide ratio 1:1. Even space shuttle had around 4:1 and it had higher higher wing loading and lower aspect ratio than most fighters. Also don't forget that aircraft needs thrust/weight higher than drag/lift (inverse of glide ratio) and modern fighters have thrust/weight just around 1, older had less. The wikipedia page lists F-104 with thrust/weight 0.54 at MTOW and lift/drag (glide ratio) 9.2 and that plane was extremely inefficient at slow speeds.

Agreed, an F-104 in "clean" configuration has much better than 1:1.  Ditto for the F-16.  Load it up with external stores (increased aerodynamic drag and increased weight) and watch that drop.  Additionally, glide ratio varies with speed.  Faster = lower glide ratio.  The Wikipedia page on the the Space Shuttle indicates that glide ratio varies from 1:1 (hypersonic) to 4.5:1 (approach speed).  For an F-16, with external stores, at high speed, 1:1 is not far off. When the engine dies on an F-16, first orders of business are: punch external stores and decelerate to more efficient speed.

True, at max speed the lift/drag ratio equals weight/thrust, otherwise you'd still be accelerating. However when you need to glide, you are going to do it at best glide speed, so that is the relevant number and when you write “lift/drag ratio” without further qualification, most people will assume it's the best achievable lift/drag ratio.

Increased weight shouldn't have a big effect on the glide ratio and should only increase the speed for optimal gliding, I think. External stores still increase drag of course.

@JulianHzg weight per se (without additional drag) does not affect glide ratio $E$, but for sure the speed for $E_{max}$ ;-)

Most wings have a given lift/drag ratio for given speed.  More weight = more lift required = more drag.  More drag = lower glide ratio.  In that regard, yes, more internal weight (even without additional, external stores causing more aerodynamic drag) can give you a lower glide ratio.  An F-16 in "lawn dart mode" with a full, internal fuel load doesn't glide as far as one that's nearly out of fuel.

@Meower68: So glide faster to keep your glide ratio close to optimal.

If the shuttle can glide to a landing, so can a fighter aircraft. Gliders have speed brakes to control the glide path angle, and the fighter can vary the angle of attack, which works in much the same way. Also, it can slalom towards the field, so if the pilot picks a landing site close and long enough, the landing is no big problem. Landing gears are normally designed to fall out with gravity alone if the locking mechanism is unlocked. However, I doubt the pilot will be able to deploy all the high lift devices, so the touchdown speed will be rather high.
On modern fighter aircraft with artificial stability, the avionics and hydraulic pumps need to work, or the aircraft will not be controllable by a human pilot. In that case, ejection is probably the safest option if all engines fail. If the glide takes more than only a few minutes, hydraulic pressure will have been lost shortly after the engine(s) and any auxiliary power unit (EPU) stop running, and even if the battery-powered flight computer still gives the correct commands, the actuators will not work anymore. Fighters need to be light, so running times of EPUs are only a few minutes, mostly.
For a successful flare, an aircraft needs a minimum L/D of approximately 5, so it will fly even if no more altitude can be spent during the landing rotation. The only aircraft I ever "met" which did not fulfill this criterium was the European return vehicle project "Hermes" before it got winglets. They were added to make the transition between final approach and touchdown flyable. Hermes was never built, so all these landings happened purely in a computer.

Shuttle aerodynamics are so awful that any fighter aircraft can beat it hands down in gliding characteristics (if the wing stations are not stuffed with ordnance, that is).

@Articuno: Yes!

The shuttle was often described as having "the aerodynamics of a highly polished brick." Exaggeration of course, but it makes the point that it's one of the worst anyone has voluntarily flown.

in fact the shuttle was designed to glide, albeit only at rather higher speeds than most people associate with gliders.

Any aircraft that can fly can glide, provided that the controls are working, and if an unstable fighter design, the [stabilizing] computer is also working. If the controls aren't working, the best glide ratio in the business ain't gonna help.

@keshlam it would be fairer to say the shuttle has aerodynamics optimized to avoid melting at hypersonic speeds.  The extremely blunt curves on its leading edges were used because while sharper edges would have less total drag they'd get hotter than the thermal protection system could handle.

"hydraulic pressure will have been lost shortly after the engine(s) stop(s) running", aren't RATs supposed to power (at least limited) hydraulics? Or are you saying modern fighter aircrafts don't have RATs or similar back up systems?

@DanNeely: Valid point, thanks. It's still a bit of a dancing bear -- the impressive thing is not how well it dances, but that it dances at all.

@falstro: Few fighters have RATs, but normally there is a EPU on board. In case of the F-16 it is hydrazine-powered (nasty stuff). And yes, it does provide emergency hydraulic power. But not for long.

Descent Characteristics of the A7-E
The A7-E, which has been retired for a while, was a single-seat, light-attack jet. The glide ratio of this aircraft is about 12:1. This is calculated for a windmilling engine (2-3 %rpm), aircraft gross weight at 23,000 pounds, drag count of 30, and no wind. With an initial altitude of 35,000 feet (5.76 nm), and a maximum range descent speed of 209 KCAS, the aircraft will travel 69 nautical miles. This performance will be worse if the engine is seized.
Without an engine the A7-E didn't fly very well, and dead stick landings were prohibited. If I remember correctly this was true for 2 reasons:

Hydraulics on the Emergency Power Package were not optimal, and quick movements of the controls could freeze them.
In an engine off approach it would be very difficult to stay within the ejection seat envelope, and towards the end of the approach the pilot would actually find themselves outside the ejection seat capability.

 Flameout Approach and Landing
If flameout occurs below 1,500 feet and below 250 KIAS, no restart was to be attempted and the pilot was to eject. If airspeed was above 250 KIAS, the excess speed could be converted into altitude, and a restart of the engine attempted. Again, if the restart was unsuccessful procedures dictated the pilot eject. The approach is aggressive.
The flameout approach and landing is a procedure to be used only if the pilot cannot eject from the aircraft. All external stores are jettisoned to reduce drag as much as possible. In this configuration the aircraft will lose 5,000 feet in a 360 degree 30 degree turn. The "high key position" is at 175 KIAS and 5,000 feet with gear down, coming in perpendicular to the runway.
Low key position is 3,200 feet and 175 KIAS, transitioning to the 90 degree position of 1,500 feet and 175 KIAS. Final is at 500 feet and 175 knots, and the aircraft is flared at 50 feet. Touchdown 3,000 feet from approach end at 155 KIAS. The Emergency Power Package will not supply adequate flight control pressure below 125 KIAS.
 Normal Carrier Approach
The normal approach for us was the 180 position with gear and flaps down at 600 feet at approximately 125 knots. For situations such as engine oil pressure low, critically low fuel, engine fire, or in other words possible engine failure, a precautionary approach was required. It will keep the pilot within the ejection seat envelope throughout the approach.
 Precautionary Approach
The precautionary approach had the aircraft at the normal distance abeam, 180 degree position at 2,000 feet with the gear and flaps down. The Emergency Power Unit would be deployed. This provided limited hydraulic power in the advent of power loss, as well as basic electrical power. The speed brake might be needed to manage airspeed in the descent to the field. The power was set at 75% and the aircraft airspeed at 150 knots. The normal 90 degree position would be hit at 1,000 feet, instead of the normal 450 feet. At the 45 degree position and runway made, gear down, reduce power to flared landing.
I remember doing the Precautionary Approach after taking a bird strike near the intake at the target. Only touched the power a few times, minimized g-loading. Out of the target set the maximum range climb rate, called an emergency with ATC, planned the descent. Came in high and fast to hit the 180 at 150 knots and 2,000 feet. It was quite a ride compared to the sedate carrier landing pattern.
If the engine flames out roll wings level, stop descent, using excess airspeed, and EJECT.

The 7:1 glide ratio would give 7000ft forward for every 1000ft vertical as you have suggested. I very much doubt that it has a ratio of 1:7 (although cannot find the actual glide ratio quoted anywhere), as the Apollo Crew Module (used for re-entry) had a glide ratio of approx 1:3 - and it was simply a dome.

Prior to writing this I did look through both the NATOPS Flight and Weapons manual, and did not find the ratio there. Coming through training this is what I was told by an instructor, and it is possible that he had it wrong. On the other hand the Martin Baker ejection seat had a 0-0 capability and a dead stick landing is prohibited in the NATOPS flight manual. I guess that would be my point. We did not "glide" the A7E to a landing because it fell like a rock, and took you out of the ejection seat envelope. Your comment is important though, and I will continue to try to verify that ratio.

I did some more digging, and updated the text. The glide ratio for a windmilling engine is 12:1. It is possible that the glide ratio of 7:1 is for the case of a seized engine.

@Aaron: If the A-7 had a zero-zero ejection seat, how would a deadstick landing take it out of the ejection envelope, given that part of the definition of a zero-zero seat is that the ejection envelope extends all the way down to ground level?

Zero-zero means zero airspeed (velocity) and zero altitude. I f you have a downward velocity then your airspeed is negative (scalar) and therefore below zero.

@Aaron: Right, but your altitude is still positive, which should balance out the negative vertical airspeed (and, when your altitude approaches zero, your vertical airspeed is also going to zero, since you're flaring to land).

Well if you flare then your vertical descent is either zero or positive and you are then at zero-zero or better. If you can't convert airspeed to altitude (perhaps you are near or at stall)  then you are below the capabilities of the seat. I posted the NATOPS ejection procedures if you are still not convinced. At any rate ejecting at the envelope boundary is like throwing the dice.

One of the most important things I learned ( in my opinion) when I played around with flight simulators is that all planes can glide. Every aircraft has a "glide plane" which is basically an angle of approach to the ground where you won't stall. The angle depends on the physical characteristics of the plane (wings, etc.). So if you lose power, you can always glide to the ground. The problem is whether your glide plane is wide enough to allow you to reach an airport. You can think of the glide plane as basically telling you that you will drop X feet every Y minutes. So if you want to land at airport you have to time it right (you can also point the nose down to increase speed and approach the ground faster, if you don't have enough glide path left to circle the airport completely.)

To help put the discussion of a dead stick landing in perspective here is the ejection seat envelope for a fighter jet.
Thought I would provide the ejection emergency procedure for the A7-E. There are several factors that go into the ejection envelope, e.g. pilot reaction time of 2 seconds. But you can see from the documentation that the last 40 feet of the approach are outside the envelope, unless you can stop the descent. When you stop the descent then you would be at positive altitude and zero airspeed, which is better than zero-zero. At that point of a standard approach one must be careful because you are at the edge of the envelope. At the edge means something like one swing in the shoot before hitting the ground.
The procedure for the dead stick landing is EJECT. If you can't eject and have to land with a windmilling engine you will not be inside the ejection envelope for the last part of the descent. The dead stick approach has very high rates of descent. Another consideration that makes this approach so dangerous is that as airspeed decreases, emergency hydraulics have limited effectiveness. One can't juts yank the stick to stop your descent. The stick will freeze. The comment in the manual is "You better be an exceptional pilot to attempt this!"
I would bail out before I would take a dead stick landing.It is like why they give old-timers a zero visibility and zero cloud ceiling height clearance to take off. They know these pilots would never use it.

Here is another look at the envelope given dive angle and airspeed. You will see that there is no safe ejection at zero-zero for any dive angle. The closer you approach a zero degree dive the closer you are being in the envelope, but nonetheless you are still just a bit outside.
Again "zero airspeed and zero altitude" means that. If you are at zero altitude and have any descent you are outside the ejection envelope. If you are at zero altitude and have any rate of climb you are inside the ejection seat capabilities. Judging exactly where you are when close to the boundary is a very dangerous decision that probably should have been made earlier.

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What are the options for installing ADS-B OUT in a Cessna Citation to meet the regulations?
So I have a friend that works for a company that owns a Cessna Citation. His company is looking to comply with the ADS-B regulations. He has been given the task of making a business case for actually doing this, but so far the only thing he's turning up is companies that want to sell the Garmin solution (GTX-345).
The specific questions:

Are there other manufacturers of ADS-B equipment that are recommended (by AOPA, FAA, or any other respectable group)?
What companies (again, respectable) would do installations? Maybe towards the Northeast since that's where he is located.
What sort of considerations do you have to look out for in upgrading to ADS-B? I am assuming it's a transponder replacement that you end up doing, but it also has to tie into a bunch of other equipment. What are the gotchas?

Cessna surely has a solution for this, has he contacted them? Usually the "firmware" of the Mode-S transponder can be updated to the latest ADS-B version (version 2, ED-102A/DO-260B). Then the GPS receiver has to be compliant with the ADS-B rule you want to fly under and connected to the transponder.  I assume you are from the USA, so the GPS receiver needs to be WAAS compatible.

Do you know what Citation model it is? And what age?

Does this link to Freeflight help? http://www.freeflightsystems.com/products/ads-b

I find it suspicious your friend would have to make a case at all. If the upgrade is not done by the mandate date the aircraft will sit (or fly outside Class A/B/C). They own a Citation, a jet and they should have their local Cessna service center do the work (these are certified by Cessna, which makes them reputable, I can't imagine they don't have a preferred service shop). The service center will have equipment that will integrate with existing WAAS equipment and can recommend the cheapest upgrade route.

The level of questions being asked indicate that your friend's employers fundamentally misunderstand the ADS-B issue. The cheapest way to resolve this is to contact the nearest Textron/Cessna service center and take their advice. Concocting a compliance strategy from where he sits now is not a wise move. There are very specific combinations of equipment approved for installation. He can't slam together a 1090 solution by stuffing any Mode S and WAAS unit into the panel.

It depends on what kind of Citation you are talking about.
I found a presentation by Textron(ppt) that discusses ADS-B installation for various models. Textron is focussing on creating Service Bulletins (SB) for installation of ADS-B on recent models (up to 15-20 years old).
For the Cessna Citation a SB is available for the following models:

Pro Line 21

CJ1+: SB525A-34-90
CJ2+: SB525A-34-41
CJ3: SB525B-34-26
CJ4: SB525C-34-09 R1
Encore+: SB560-34-163
XLS+: SB560XL-34-76

Sovereign

Primus EPIC: SB680-34-33 R1

Citation X

Primus 2000: SB750-34-58

For the following
Cessna Citation SB's are under development (when the presentation was given)

Ultra, Encore, XL, XLS

Primus 1000; expected Q2 2016; Prerequisite: Universal FMS with SBAS LPV

Mustang

G1000; expected Q2 2016

It is possible to install another transponder than advised by Cessna. However if it hasn't been done already, you have to go through a Supplemental Type Certificate (STC) process for that which makes it rather expensive. It also wouldn't be supported by Cessna, which will impact the resale value of the aircraft. You may offset the cost of the STC by offering it to other Citation operators, but then you are suddenly in a whole different kind of business.
Other considerations to take into account are support of future operations, mainly LPV approaches using the same GPS receiver.

Since all offers seem to prefer the Garmin GTX, I assume the aircraft is a Cessna Citation CJ1 or CJ2 with a non-Collins FMS. Cessna has a STC for this aircraft that is based on the Garmin GTX.

Are there other manufacturers of ADS-B equipment that are recommended
  (by AOPA, FAA, or any other respectable group)?

There are other makers out there making transponders but Garmin is a very highly respected avionics maker.

What companies (again, respectable) would do installations? Maybe
  towards the Northeast since that's where he is located.

Any decent avionics shop should be able to do the install. I presume someone does the maintenance on the plane currently, they should be more than capable of an install like this or have a go to avionics shop that can help out. As mentioned in the comments Cessna may have someone or be able to point you to someone.

What sort of considerations do you have to look out for in upgrading
  to ADS-B? I am assuming it's a transponder replacement that you end up
  doing, but it also has to tie into a bunch of other equipment. What
  are the gotchas?

ADS-B may be able to play well with your other equipment but that cant be answered unless you tell us what the plane is currently outfitted with. If it is an older cockpit with steam gauges and traditional radios there is not much to wire it into. However if its a new glass cockpit there may be more options for wiring it in.

From my understanding, there's a difference between updating the CJ2 and CJ2+. The straight 2 can get Garmin ES transponders and a GTN-750. But the 2+ has more integrated avionics, and must have a Collins solution that is more expensive and complicated. Ironically, the older the jet, the easier it is to update to ADS-B. The early 500/550 series Citations had a ADS-B solution 2 years ago. I've heard the Beech Premier is a real problem, because it requires new antennas, and the composite construction makes retrofitting difficult. Also, not jets, but the G series Bonanza and Baron owners are getting the runaround with updating the G1000.

When looking for potential ADS-B Out installations, one might consider first looking at the FAA's website of approved installations. After doing a search there, contact a vendor who may offer that solution. In cooperation with avionics manufacturers, the FAA maintains a list of approved installations:
List of certified ADS-B Out installations.
They also maintain a searchable database by aircraft:
Searchable database  This information is directly from the manufacturers and provided by the FAA.

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Why do airplanes start descending when we initiate a left turn?
Today I watched a video about the Fly-by-Wire (FBW) system (see below) and at 3:20 there is a left turn initiated in a Cessna 152. Then it is shown that with a left turn (only by ailerons), in aircraft with a mechanical flight control system, it will start a descend (and a slip).
I understand why the aircraft starts flying a slipping turn, but I don't understand why it start descending. Because gyroscopic effect would make the aircraft to pitch up in a left turn.
It is also said that each aircraft with mechanical flight control system, either little Cessna or Boeing 737, will have that tendency. Can somebody explain that descending tendency?
My guess is that the turn is initiated without power increase, so to stay with the same indicated airspeed the aircraft must be pitched down, but I'm not sure of that.

Why do you think that gyroscopic effects make the aircraft pitch up in a left turn?

Wouldn’t it with clockwise rotating prop? Correct me if I’m wrong. Of course im not talking about jet.

The rate of rotation is too slow to notice that sort of thing in that circumstance.  The only time you notice precession from a propeller is things like taking off a taildragger and raising the tail off the ground abruptly early in the roll.  You will get a swing to the left from that.  A noticeable pitching action from precession would have to come from a hard rudder yawing input, not from rolling into a turn where the rotation about the yaw axis is very gentle.

There is a problem with this question.  That video is not from any real plane.  It is from a computer simulation.  I guarantee you that if you do the same maneuver (without using the rudder pedals) in a real Cessna 152, you will find that the displacement of the slip-skid ball is much more related to roll rate (and likewise to aileron displacement), and much less related to bank angle, than is shown in this video.

In particular in the interval from 3:42 to 3:46 the aircraft is actually rolling at a substantial roll rate toward the high wingtip, yet the ball remains displaced toward the low wingtip.  This would not happen in a real Cessna 152.

Humm... Just thinking here, but if you use just the ailerons to turn, it's an uncoordinated turn and you have a bit of a slip.  Which means you've increased drag, no?  So if you maintain the same airspeed & power, you descend.

This is because when you roll left (or right), the lift changes from pushing up to pushing up + left (or + right). This is what makes you turn. Since some of that lift is being used to the left (or right), not as much is pushing up, causing the plane to lose a bit of altitude. On FlyByWire aircraft, since they are computer-controlled, the computer automatically compensates for this by adjusting elevators to pitch up slightly.

Imagine a line extending up from the center of the wing perpendicular to the chord line of the wing. This is the lift vector. It points more-or-less straight up in level flight. In this scenario, 100% of the aircraft's lift is pointing up. If we roll into a turn, now some of that lift is pointing sideways- that pulls the aircraft sideways, which pulls it through the turn. That horizontal component of lift is subtracted from the vertical component, and that means that weight now exceeds lift. This causes a descent. For the same reason, when you roll out of a turn without elevator input, you'll balloon upward. To fly a level turn, we need to increase lift. To do this, we can (assuming the wing is not near the critical AOA) increase the angle of attack by putting back pressure on the elevator. By doing this, we increase lift and stop the descent.
https://www.boldmethod.com/learn-to-fly/aerodynamics/the-aerodynamics-of-a-turn-in-an-airplane/

Re "If we roll into a turn, now some of that lift is pointing sideways- that pulls the aircraft sideways, which causes the slip." -- a steady sideways force simply represents the centripetal force that makes the aircraft follow a circular path.  There's no reason for that to automatically make the aircraft slip sideways through the air (except for the effect of yaw rotational inertia causing some slight delay in getting the required yaw rotation rate established as the turn is first starting.)

So you have to look to other aerodynamic effects to explain any sideslipping tendency during a sustained turn.  (I.e., once the bank angle has been established and maintained for more than just a few seconds, yaw rotational inertial shouldn't be a factor any more, so the explanation that the sideways "push" from the banked wing should automatically tend to cause a sideslip doesn't really hold up.)

Revised it to be a bit more accurate.

Much better explanation than mine :)

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


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Was this bumpy Boeing 777-300 landing caused by windshear?
I was watching a Video of a Korean Air 777-300 landing at Narita International Airport (IATA: NRT). The Comments on the YouTube Video are again unprofessional.

I want to ask here, what caused this very bumpy landing?
Some comments state this was a wind-shear, is that correct?
Is required by rule to make a maintenance check after such a landing?

Comments elsewhere suggest a 777-300 at Narita International in strong/gusting crosswinds.

any landing that everybody walks away from is a good landing.
any landing where you can also re-use the aircraft is a great landing.

Some comments state this was a wind-shear, is that correct?

Looking at the windsock which appears in the right bottom corner at 0:12 and remains visible for about 4 seconds, you can tell there is little wind, not what you would associate with wind shear.

I want to ask here, what caused this very bumpy landing?

It is always hard to judge the actions of the pilots without knowing what was going on in the cockpit, and what control inputs were given. But by looking at the position of the control surfaces I am fairly sure that this is a case of Pilot Induced Oscillations. I.e. the pilot tries to correct a disturbance but his efforts cause the aircraft to overshoot to the other side of the desired attitude, leading to an increasing series of corrections in opposite directions.
It seems to me that the flare is a tad early, causing the aircraft to float over the runway. At the same time several cycles of alternating roll inputs are given, causing increasing oscillations. I could distinguish at least 3 full cycles before touchdown. Every cycle is a bit stronger than the previous one.
The last right-wind-down command before touchdown is strong enough for all the starboard spoiler to deflect. This, combined with the low speed due to early flare causes the right wing to loose most of its lift. The aircraft touches down hard on its right gear first. At the moment of touchdown, the roll command is strongly left wing down as can be seen from the spoiler extension on the left wing. With almost no lift on the left side and standing on the right gear, the aircraft rapidly rolls to the left.
The left roll is then counteracted again with right ailerons up but too late; the right gear lifts of again. When then right gear touches for the second time, still a right wing down command is given, causing the right roll to continue.
This process of chasing the roll is continued and mixed with similar behaviour in pitch.

Command right wing down, slight spoiler deflection

Command left wing down, slight spoiler deflection

Command right wing down, slight spoiler deflection

Command left wing down, slight spoiler deflection

Command right wing down, right spoiler deflection.

Touch right gear down,  left wing down, left spoiler deflection. This causes a rapid left roll.

Touch left gear down, right gear looses contact, right side spoiler deflection. This causes a rapid right roll.

Halfway the roll to the right, all main wheels are on the ground. Instead of damping the roll by left deflection, a right roll is still commanded.

This continues down the runway, also combined with pitch oscillations. Every time the pilot corrects, he is essentially too late to damp the oscillations.

Is required by rule to make a maintenance check after such a landing?

If a hard landing is made, the aircraft will detect that by itself and will send a report to maintenance if a hard landing check is required. See this published patent application.

How did it happen?
I watched the video closely and coordinated the movement of the ailerons with the motion of the plane.
It appears to me that there was a strong gust from the left moments before touchdown. As a result the left wing is lifted by the crosswind and the aircraft, still in the air, side-skid to the right. Exactly when the right main gear touches the ground, the gust dies down and the pilot has input left aileron to counter the roll. This initiated the bouncing sequence.
In all the subsequent bouncing, the pilot was trying to determine how much left aileron is necessary to counter the crosswind. The technique is correct, but the crosswind now is much weaker than it was 2 seconds ago; he also had to level the wings which are rolled left at this point. Unfortunately the rhythm he applies correction matches with the rhythm the plane bounces, resulting in a brief pilot induced oscillation.
Wind shear?
I agree with RedGrittyBrick - I wouldn't call the gust at an altitude of a few feet a wind shear.
Maintenance check required?
In some airplanes the g-meter needle stops at the peak value during the flight. If it exceeds a certain threshold, a check is required. I'm not a real life 777 pilot, but my knowledge of the 777 does not recall such an instrument in the cockpit.
Required or not, good airmanship should lead the crew to write this down in the maintenance log for ground engineers to review. Personally I don't think this was a particularly hard landing that would lead to bent parts, though my instructor would remind me: "when it doubt, take the safe way".

Airliners generally don't have g-meter indicator in cockpit, but the avionics generates a report for maintenance as part of post-flight if the G limit was exceeded.

what caused this very bumpy landing?

It looks like it was initially triggered by a sudden change in crosswinds, a strong gust,  perhaps a microburst?
It looks like the pilot then had trouble correcting for the bounce of the right side undercarriage at the same time as dealing with the crosswinds lifting the wings while simultaneously keeping the aircraft aligned on the runway.

Some comments state this was a wind-shear, is that correct?

From what I've read, the term wind-shear is mostly used of sudden differences in wind direction and speed at different altitudes, it wouldn't apply a few feet above a runway. It could be a downburst or microburst though - they are related phenomenon.

Is required by rule to make a maintenance check after such a landing?

I've read that the airline ground-crew can read-out the G-forces  experienced during landing and vertical speed at touchdown. If certain thresholds were exceeded, checks would be carried out.
Airlines are required by ICAO to use Flight Data Monitoring (FDM) to improve safety.

From CAA CAP 739 Flight Data Monitoring

Microburst is what usually causes wind-shear and even though they are "micro" they are still somewhat bigger. This might have been just a strong gust.

@JanHudec that's incorrect; wind shear is usually caused by a high differential between layers. Microbursts are uncommon.

@Jan, I've edited the answer to encompass the possibility of a strong gust.

@JanHudec A microburst would have pushed the plane downwards, not sideways. And at that altitude, it probably would have crashed. The best way to deal with a microburst while flying is to not be flying anywhere close to a microburst (which can generally be accomplished by staying away from thunderstorms.)

@reirab: A microburst can push the plane sideways if it hits the ground beside the aircraft. But yes, storms that could create microbursts should just be avoided altogether. The airport would probably be closed when one is directly over the runway.

@RedGrittyBrick - Downbursts and microbursts aren't "related phenomenon", they're the same thing.  One is just bigger than the other.

@SteveV. I parsed it as "downbursts and microbursts are phenomena related to windsheer" not "related to each other".

That landing wasn't pretty, but I wouldn't describe it as hard to the point of damaging the aircraft. A bit firm, followed by some oscillation is a better description. Not something that would warrant a maintenance inspection in any case.
One thing about oscillations is that you can often make them worse by using control inputs to even them out. It's usually better to ride them out, which is what looks like is happening in this case. Remember that the aircraft is not out of control just because it bounces.
If you do enough landings one is eventually going to get ugly even if you've set everything up right. You have a good approach speed, set up a good flare, then suddenly the whole thing drops onto the surface and next thing you know you're skipping down the runway like a flat stone. This is rare in clear air, usually this happens when there is a crosswind which has blown across some structures which have caused pockets of lower air pressure.


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What is the purpose of the inlet doors of the Pratt & Whitney JT3D?
I have a question about the 707 Engine Inlet Doors, according to Wikipedia the Pratt & Whitney JT3D inlet doors purpose is to provide additional air. Is the thrust higher on more air intake? And why modern engines don't have it anymore?

The intake speed at the compressor is between Mach 0.4 and Mach 0.5 and changes little with airspeed. That means that at low speed the intake has to suck in air from a wide capture area, (even from behind the inlet lip at low speed) while at high speed only the part that flows into the center of the intake is digested, while surrounding air will spill over the intake lip and flow around the nacelle.
The surface that separates the flow going into the engine and that which does not is called the stagnation stream line or surface. This surface is way aft of the inlet lip at low speed, and the pressure near it is the highest (stagnation pressure). The challenge for the inlet designer is to design the lip with a rounded shape so that the flow going into the engine is uniform. It won't be if the lip is as shaped in the sketch. The high pressure on the outside and the low pressure inside the lip open the doors to admit a small percentage of the air to the engine inlet at low speed. As airplane speed increases, the stagnation point (or line) shifts to the lip itself and the pressure equalizes on the doors, closing them.

The fairly sharp intake lip of the JT3D will capture air rather inefficiently at low speeds (the topmost case in the sketch above), which could even lead to flow separation right after the intake lip, reducing mass flow and compressor efficiency. By adding the suction-activated doors, the intake can capture more air and keep the flow attached.
More recent intake designs have thicker intake lips, so the flow stays attached even at very low airspeed.

How sensitive to either design (with and without doors) are the engines at high angles of attack where the relative direction of the ambient airflow is not fully aligned with the engine?

@SkipMiller: This question is worthy to be asked officially and not hidden in a comment. The biggest angle changes you see with supersonic combat aircraft, and the short answer is: It needs a lot of optimization to make intakes work well. Low speed with high angle of attack is one sensitive point, and the other is supersonic flight with sideslip or unusual angle of attack. Airliners have less angle of attack variation, so their intakes are fairly easy to design.

I presume this is then similar to the series of radial suck-in auxiliary doors on that AV-8B harrier as well?

@CarloFelicione: Absolutely! In case of the Harrier, it needs a lot of air while standing still - the intake is already much bigger than that of comparable conventional jets, but the blow-in doors are still needed so the Harrier can hover.


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Rules and restriction for toy UAV in India on very low heights ? (max 50 meter from ground )
We want use RC UAV to take some pictures of  heritage forts (Gadh) around Pune. Do I need a special permission for that ? I have seen some one doing it before but just for to be sure I need to know. is there any official government website that can guide us ? I am so concerned because I want to do a research project.

I'm voting to close this question as off-topic because it is effectively seeking legal advice and StackExchange is not the right place to get this.

@Simon we already had similar question and they have not been closed. This is more about aviation-related regulations rather than "advice".

@Federico Which is why close needs multiple votes ;)

@Simon I know, I was just explaining, the same way you did ;)

A public notice issued by the DGCA in October reads: “DGCA is in the process of formulating the regulations [and globally harmonise those] for certification & operation for use of Unmanned aircraft systems [UAS] in the Indian Civil Airspace. Till such regulations are issued, no non-government agency, organisation, or an individual will launch a UAS in Indian Civil Airspace for any purpose whatsoever.”

...

“There are no regulatory guidelines concerning the sales and operation of such aircraft. So when a request is made for the use of drones we allow it on a ‘case-by-case’ basis. If we feel that they would not pose any security threat or cause any traffic snarls, we allow the request,” explained another senior police officer.

The Hindu, December 24 2014

Thanks RedGrittyBrick instead of complaining like others you found the right answer must appreciate your searching skills plus your attitude and understanding level. Thanks a lot.


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Does ATC provide ILS frequency and course setting for the runway in use?
I'm just from FSX background and not familiar with real procedures. In real world situations, when the pilot is vectored to the runway, does the ATC provide the pilot with the runway frequency and course setting or does the pilot have to know these already from somewhere (logs, FMS, etc)?
I mean in a real world case does ATC say for example "Expect ILS runway 24 left" or do they tell the pilot the nav frequency and course setting too? Or does the pilot obtain the setting for approach like the FSX GPS?
If possible please provide me with a sample communication for landing between ATC and Pilot. (Really curious)

In real world a pilot performing an instrument approach would always have the approach plate (chart) handy, in either paper or electronic form. This includes the required details including not just frequency and course, but weather minima and the missed approach procedure. In an emergency, of course, he can always ask the tower for the relevant numbers.

VATSIM or IVAO. You can practice the exact procedures and comms used in the real world.  Short summary, you will expect a runway from the ATIS and from the approach controller on first contact.  ATC will typically vector you from the end of the SID to the ILS and will clear your approach "cleared ILS 27L approach, report established".  When you capture and are stable on the localiser, you report established and you will hear something like "continue the approach, speed 180 kts, descend with the glideslope" later followed by "4 DME, contact the tower on 121.8".  Tower will clear you to land.

When nearing their destination, pilots will be checking weather and airport information. This will let them know which runways are being used for landings and what type of approaches are being used. ATC will also tell each aircraft what runway and approach they can expect in advance, as in your example, "Expect ILS approach runway 24 left".
Once the pilots know the runway and approach, they can reference the corresponding chart (like the ones in this question). Pilots are required to have these charts available, traditionally paper copies but more recently being replaced by electronic copies. This will give them all of the information about the procedure, including the localizer frequency. Besides programming the frequency, the crew will also review the other important requirements of the approach and landing.
ATC does have access to this information as well, and can provide it if they feel they need to confirm the pilot has the right frequency, or if the pilot asks.

And of course we (the pilots) have the option of requesting an alternate runway and/or type of approach.

In my world, we call those plates. Charts are maps. Although low altitude IFR charts do have ILS info

If e.g. a pilot were to spill something on the approach plate that rendered illegible, I would expect that ATC should have no qualm about supplying whatever information the pilot needed without the pilot having to declare an emergency.


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How should the VFR Cruising Altitudes (FAR 91.159) be applied over rising terrain?
Imagine flying at 4500' indicated altitude, 4500' AGL, heading 270, directly towards a steep mountain ridge that tops out at 4000 feet.  Imagine the mountain being almost like a flat wall.
When can I change altitudes to >4500' and still be in compliance with 91.159?  Do I have to wait until I get close to the ridge when I'll be under "3,000 feet above the surface"?  Can I interpret "above the surface" in a more liberal way?

§ 91.159 VFR cruising altitude or flight level.
Except while holding in a holding pattern of 2 minutes or less, or while turning, each person operating an aircraft under VFR in level cruising flight more than 3,000 feet above the surface shall maintain the appropriate altitude or flight level prescribed below, unless otherwise authorized by ATC:
(a) When operating below 18,000 feet MSL and -
(1) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude 500 feet (such as 3,500, 5,500, or 7,500); or
(2) On a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude 500 feet (such as 4,500, 6,500, or 8,500).
(b) When operating above 18,000 feet MSL, maintain the altitude or flight level assigned by ATC.

I'm not sure I understand your question. 5500 would be an eastbound altitude, did you mean 6500? And if the ridge tops out at 4000, then the regulation only applies from 7000 at that point. But anyway, under VFR you can climb or descend whenever you want (airspace and ATC permitting) so I'm not sure what you're asking.

I'm asking: leading up to the ridge top, what constitutes as "above the surface"?  The ground level directly below me?  If so, 91.159(a)(2) is required right up until I'm over the ridge.  Is this correct?

"Above the surface" means AGL. If the ridge top is at 4000 MSL, 91.159 only applies above 7000 MSL.

Exploit the "except while turning" part of the rule:  enter into a very mild turn, and then you're free to climb whenever you want.

@Devil07 That does make more sense (and I see the OP has edited the question to clarify it). Although since it's a VFR flight, the basic answer is still "climb whenever you like".

Related

First, you said you're cruising at 4500 indicated, but then state that you are 4500 AGL. Indicated altitude is usually MSL, so this means the terrain is at 0 ft MSL until the base of the cliff, which then shoots up to 4000 MSL.
So as you travel westbound at 4500 MSL, you are in compliance with 91.159. The moment that the distance between your aircraft traveling at 4500 MSL and the ground is 3000 feet or less, then 91.159 no longer applies, and you can fly any altitude you need in order to maneuver around or over obstructions at or below 3,000 AGL.
Based on your scenario no action is required, you can just keep cruising along and fly over the cliff at 4500 MSL and 500 AGL over the "flat wall" mountain.
However, your question would be more interesting (and I'm guessing this is what you meant) if you had said that the flat wall was 5000 ft, because technically if the ground is at sea level up to the flat wall, then you are still more than 3000 AGL up until the moment your aircraft reaches the wall and 91.159 would still apply. The answer to this is that you would have to climb to the next westbound VFR altitude of 6500, and you could do it whenever its needed if you're on your own navigation, or when instructed by ATC if you are on an assigned altitude, or at anytime to avoid crashing into the mythical "flat wall" mountain.
The key is that this rule applies only during "level cruising flight" so when you are climbing or descending 91.159 does not apply, otherwise, VFR aircraft could never get to the upper VFR cruising altitudes.

as one approached the 5000' wall at a 4500' altitude, I believe one could declare an emergency since CFIT would be imminent, and then you're allowed to do basically whatever you needed to do to avoid the collision. However, applying common sense by climbing before needing to declare an emergency to avoid hitting the mythical wall would make more sense.

I think you may be over-using the term cruise or underestimating your role as PIC.
If you are maneuvering in a reasonable and predictable way to maintain obstacle/terrain clearance, then you aren’t really in cruise flight, you’re in maneuvering flight.
2nd, understand the intent behind the reg...  it doesn’t prevent IFR/VFR conflict, it just reduces it by saying “if you’re straight and level at altitude going from point A to point B, why not fly at an altitude that separates you from IFR in case a clearance or nav mistake is made.”
You are still given broad discretion to weigh the risks of flying too long a distance at the wrong altitude, vs flying too close to terrain by waiting to climb til the last moment.

That's exactly it: Mr PIC, when do YOU want to start climbing in order to have adequate, prudent clearance from the mountain?  Great, start climbing at that point!  And if you're in a climb right until the point when, having passed the mountain, you're ready to descend, nothing requires you to top out at a particular VFR crusing altitude before descending.  And, BTW, welcome to Av.SE!

As Pondlife pointed out, you can climb and descend under VFR more or less whenever you like.
Of course, if you so wanted (keeping 91.119 in mind), you could just maintain your current altitude, since in your example the mountain tops out at 4,000 MSL and you're at 4,500 MSL.

I would consider 500 ft AGL over the tops to be dangerous in the event of downdrafts.


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What is a "high-bypass geared turbofan," and why is it so much more efficient?
According to the article Bombardier’s CSeries Gamble Is Facing Longer Odds, this new plane from Bombardier uses a new engine technology that will improve efficiency over its rival 737 series and A320 series airplanes, to the point where it will be able to complete on a seat-mile efficiency basis with larger airplanes, enabling it to bypass hubs:

The linchpin for the CSeries was a new concept for engines developed
  by Pratt & Whitney, known as a high bypass geared turbofan. The new
  engine design promised exceptional fuel savings of up to 20 percent
  and unusually low noise levels.

What's the theory behind this new engine, and what are the underlying numbers that make it competitive with larger airplanes?

I think that the fan can rotate at a different speed then the compressors

The fan section of a turbofan engine is driven by the low pressure (LP) spool. This means that it is connected to two parts of the engine:

The LP compressor, which must compress the air before it enters the high pressure (HP) compressor
The LP turbine, which must receive the air after it exits the HP turbine

The problem is that the HP section is efficient at high RPM. But the fan will reach aerodynamic limits as the fan tips pass supersonic speed. Fan blades are also harder to contain in the event of a failure as they spin faster. So to accommodate the fan, the LP section has to spin at a slower speed, which makes it harder to match with the high RPM HP section.
There is also a limitation on air flow. The fan must be able to move a maximum amount of air, which is takeoff power at sea level. But it must also be able to function efficiently at cruise level, where the flow is faster but much less dense.
Engine companies use different strategies to deal with these limitations.
GE mainly makes the LP sections larger in diameter. This allows the blades to have a high velocity at lower RPM. This this requires the air flow to change direction more rapidly.

Rolls Royce has created a 3 spool design, which allows each section to spin at a more optimal RPM. This adds complexity to the design.

Pratt and Whitney is going with the geared fan approach. Similar to turboprops, there is a gearbox to allow the fan to spin at a lower speed than the engine spool that is driving it.

This allows the turbine spool to operate at a more optimal RPM while still allowing the fan to spin more slowly. A slower fan can be larger, allowing for a higher bypass ratio.
A high bypass ratio allows a turbofan engine to drive more air (produce more thrust) for less air going through the core (burn less fuel). Modern large aircraft have engines like the GE90 on the 777 (9:1 bypass), with the latest engines on the 787 going even higher with the GEnx (9.6:1 bypass), and Trent 1000 (10.8:1). Smaller aircraft like the 737 and A320 currently use engines like the CFM56 (5.5:1), with the new LEAP going higher (9:1 or 11:1). The PW1000G goes even higher (up to 12:1).

which is the engine on the CSeries? the PW1000G?

@rbp Yeah, PW1500G

The tips of modern fan blades run at Mach 1.5. There is no aerodynamic limit at Mach 1, but speed increases come with higher penalties.


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Where can I find details of the holding models for JFK, Schiphol, Heathrow and Dubai?
Does anyone know the stack (holding) models for the JFK, Schiphol, Heathrow and Dubai airports? I mean, not where the aircraft hold but rather how is it planned and what concepts are used? Or how I can find that data?

I reworded your question a little, but I'm not sure exactly what you need. Are you asking for a map of where the aircraft hold, or for details of the holding planning concepts at each airport? Or something else?

yes, tnx sir...

I mean the second one @Pondlife

Do you want to know the leg size, radius, etc? Or something else?

It looks like a homework question for university student

Why do you want to know this? :/

Most chars can be found in the local AIP. Most charts containing such data are the 'Standard Arrival' charts, such as location, heading and holding time.
For the  Netherlands (Because you asked for Schiphol) it would be http://www.ais-netherlands.nl/aim/index.html

Here is a website with some information about the holding points at Heathrow: https://nats.aero/blog/2013/06/infographic-why-do-aircraft-hold-at-heathrow-airport/
But it is really a case of trying different keywords in the search engine that are relevant.
Holdings depend on the type of aircraft - due to wake turbulence - as lighter aircraft can not land after bigger aircraft due to violent turbulence that may cause major issues. Another factor is the air traffic in the area. This affects the number of levels the controllers use in the stack. Most holding points have 15 levels - from around 10,000 feet to 26,000 feet missing out 14,000 feet as this is the point where controllers can split the stack so that they have less planes to control at one time - this increases efficiency.
As you probably know, aircraft must be 1000 feet apart from one another whilst in the stack or just generally on course.
Holding points are split into 4 parts and normally take 4 minutes to complete one loop. Each part of the loop takes 1 minute. So if the pilot has a 8 minute delay he will be told by the controller to go around twice (two four minute loops) before he can be passed over to the approach controller in preparation for landing.
This is just the basics of it really so I hope it helps.


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Is platinum present in a combustion chamber?
Platinum group of metals (PGM) are very resistant to extreme heat. Why is platinum never mentioned in aerospace world? Is this a top secret?

Related: What material is used to make the hot sections of jet engines? Density (Pt = 21.45, Ni = 8.91) and cost limit the use of platinum (and more overall, so called platinum group metals, PGM), see this article.

Use of platinum & iridium in spark plugs is quite common, so it's not true that the use is never mentioned.  E.g. http://www.championaerospace.com/products/spark-plugs

To elaborate on mins comment: platinum right now is selling for around \$1000 / troy ounce, which is ~\$14,500 / pound.  Nickel is selling for around \$4 / pound and cobalt is \$25/pound. Nickel and cobalt super alloys have sufficient temperature capability for jet engine applications.  So the choice is clear. Platinum is not mentioned because it is not used.


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Rate and radius of turn formula
From this question and answer here there is a formula for both rate of turn and radius of turn.  The formulas input are knots and degrees.
I have no doubt the constants in the formula (11.26 and 1,091) are conversions from SI to knots and degrees but can't seem to figure it out today.
Would someone walk-through how those constants were derived?
Thanks

The "real" formulas are
$$R=\frac{V^2}{g \tan \theta}$$
and
$$\omega = \frac{V}{R} = \frac{g \tan \theta}{V}$$
With $R$ in feet and $V$ in knots you get
$$g^*_R = \frac{g \cdot 1\,\mathrm{ft}}{1\,\mathrm{kt}^2} = \frac{9.81\,\mathrm{m/s^2} \cdot 0.3048\,\mathrm{m}}{(0.514\,\mathrm{m/s})^2} = 11.29$$
and with $\omega$ in degrees
$$g^*_{\omega} = \frac{g }{1\,\mathrm{kt} \cdot 1\,\mathrm{°/s}} = \frac{9.81\,\mathrm{m/s^2}}{0.514\,\mathrm{m/s} \cdot 0.01745\,\mathrm{rad/s}} = 1093$$


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What is an autogyro, and why would I ever want to fly one?
Autogyros seem to be one of those mythical creatures: we know there are actually a few of them out there and they're supposed to be fun to fly.
What are they really; how do they work? And how do you fly one?

How about reading the Autogyro Wiki page then come back and refine your question into something a little less broad? Perhaps solidify what you want to know into concrete questions with concrete answers. As it is, this would take a book to answer.

@CGCampbell The FAA wrote a book on this - The Rotorcraft Flying Handbook. (They basically tell you to ignore everything before Chapter 15 because the helicopter stuff has its own book now - one day I expect they'll have a "Gyroplane Flying Handbook")

Why you would ever want to fly one, is a question only you can answer yourself. If you are interested in the way an autogyro works, just ask that.

What is an autogyro?

Autogyros have been around for decades. They are also known as gyrocopters, gyroplanes, and autogiros. Gyroplane is the official FAA designation. It is basically a rotary wing aircraft just like a helicopter because the rotor  provides lift instead of wings like conventional airplanes.Since the rotor is not powered, an Autogyro uses a separate source for propulsion, just like an airplane. In other words, an Autogyro uses a propeller for forward motion and a freely rotating, un motorized rotor for lift.
http://www.jefflewis.net/autogyros.html

How do you fly one?

There are only three flight controls: a control stick, rudder pedals and a throttle.
Autogyros do not stall, so it is a lot safer to fly an Autogyro than say a helicopter.You can expect control responses to be faster in a Autogyro than an airplane because you are moving the whole wing  instead of just a  tiny control element attached to a wing. Generally speaking, the control response will not be as quick as a helicopter because of the lower operating rpm of the Autogyro’s rotor system.The critical task in flying a Autogyro is managing the energy of the rotor. If you fail to maintain air flowing through it, the speed drops drastically, and so does the rotor's ability to provide lift.

Autogyro certainly can stall. The difference is that it does not stall when it slows down but when the rotor slows down, so you can do vertical landing utilizing the inertia of the rotor to maintain lift for some time.

Gyros can have a Precision Stall. Gyros are in auto rotation all the time. Ergo, the pilot can easily slow up to 0 airspeed and do a vertical descent and there is no danger of it stalling. Just that the pilot will have to start regaining airspeed so that he can flare to land softly

Of course they are in autorotion all the time. But sustaining autorotation requires forward speed; once the gyro slows down for landing, it must touch down before it runs out of rotor energy, so it may only slow down when already low above the landing area. Remember helicopters have a range of altitudes from which autorotational landing is not possible if the helicopter was in hover, but it is possible when the helicopter was flying.


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What options are there to learning IFR flying on Garmin's G1000 (Cirrus Perspective)?
I am about to begin my IFR training.  I can do this in a 5-year old 172 with the G1000 at a reasonable price.  I need a good tutorial or book for learning IFR with the avionics on which I plan to learn.  In particular, I do not first want to study avionics that I neither have seen nor operated, only so that I can then unlearn them and relearn how the G1000 has morphed their functionality.  Ideally, I would take a course that imagines that IFR was invented together with the G1000.  My particular situation is likely to become more common over the years, too, with wider spread of the G1000 and alike.
I have searched the net.

There is a book by Max Trescott, but it dates from 2012.  It is 2018 now.  Has the G1000 software since 2002 received some good or important updates ?!
There is an expensive course by King Schools.
There are the official Garmin manuals.

Are there any other options for training on the G1000? What are the advantages and disadvantages of these options?
Note: I am not affiliated with any of these vendors, nor do I have any information.  I am just looking for discussions of pluses and minuses of updated G1000 IFR books, courses, and tutorials.

There are some G1000 simulator apps for the iPad.

You can get books on the subject, but one of the best ways to learn the G1000 is practice.  Fortunately, Garmin sells a G1000 simulator which can be installed on your computer and replicates all of the G1000’s capabilities.  Along with a joystick and throttle you can plan and execute flight, fly approaches, and practice anything else on your PC.  They are available in a variety of G1000 setups, including the Cirrus Perspective.  Cost is $25.
https://buy.garmin.com/en-US/US/p/35045

I can attest to Garmin's G1000 simulator being an excellent and effective training tool. I used it extensively when I started flying King Airs equipped with the G1000 flight deck, and that practice helped tremendously in transitioning to that avionics suite in the real aircraft.


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Relation between Squawk code and ICAO adress
I can see in ADS-B downlink format 5 or 21, it is possible to answer squawk code. I am wondering how ATC will know which squawk  code is coming from which aircraft? There is no possibility to encode ICAO address in downlink format 5 or 21 . However, address parity finally result a uncontrollable ICAO address.

The ICAO 24-bit aircraft address is encoded in every ADS-B (Downlink Format = 17) message. It is the primary means of associating messages to the same aircraft in ADS-B.
What you have in your question is not an ADS-B message but a surveillance identity reply (DF = 5). This is the reply to a Mode S radar interrogation. The Mode S radar already knew the 24-bit address of the aircraft when it asked the transponder to send a short (DF = 5) or long (DF = 21) identify reply.
The Mode S radar verifies the aircraft address during the parity check and reports the 24 bit address, squawk code, azimuth, range and additional information to the ATC surveillance data processing system.
The air traffic controllers do not use the 24 bit address; this is only used in the data processing. The air traffic controllers see the position of the aircraft on their display, with a label containing the squawk code and other information.

Thanks you very much

@KamalKhatan, your welcome. If this answered your question, consider accepting it by clicking the tick mark below the vote buttons.


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What are the regulations and testing that determine whether a "Spins Prohibited" placard is required in an aircraft?
Clearly some flight testing and certification process is used to establish whether or not a type of production GA aircraft is or is not placarded "SPINS PROHIBITED". What type of testing and what results determine the outcome/certification? What does such a result mean for the aircraft's actual performance in a spin/recovery situation? I know spin certification is completed with a recovery parachute mounted to the tail in case of an unrecoverable spin and that an aircraft must recover within 6 turns to be certified (unless you are Cirrus and have a parachute) but what else is there?

So if there is a "SPINS PROHIBITED" placard that means the a/c is not certified for spin recovery? Therefore you should not intentionally initiate a spin for practice?

@TomMcW In effect it means what you said - "you should not intentionally initiate a spin"... The unsaid rest of that statement is ..."because you might not be able to get out of it and may ride the spin into the ground". As part of certification airplanes must demonstrate that they can recover from a spin either aerodynamically like most planes or by some other means like a parachute, in the case of Cirrus.

So are some aircraft not certified? Well, probably experimental craft, but I mean are any regular production aircraft not spin certified ot is that an FAA requirement?

@TomMcW to my knowledge (I'm a pilot but not a complete FAA rules guru - I did ask this question after all) all "small" civil aircraft must be certified for spin recovery. It may (ought to in my view) be required for airliners/large aircraft too but I suspect the rules are different.

Spins require a demonstration for certification, but can be bypassed with an FAA waiver as Cirrus did for the SR-20/22. The waiver was granted under the understanding that the only way to recover a Cirrus is to pull the chute.
FAA CFR Part 23 governs the process and requirements for certifying general aviation aircraft. Specifically for spins you are wanting to read CFR 23.221 which outlines the process of spin testing:

(a) Normal category airplanes. A single-engine, normal category airplane must be able to recover from a one-turn spin or a three-second spin, whichever takes longer, in not more than one additional turn after initiation of the first control action for recovery, or demonstrate compliance with the optional spin resistant requirements of this section.
(1) The following apply to one turn or three second spins:
(i) For both the flaps-retracted and flaps-extended conditions, the applicable airspeed limit and positive limit maneuvering load factor must not be exceeded;
(ii) No control forces or characteristic encountered during the spin or recovery may adversely affect prompt recovery;
(iii) It must be impossible to obtain unrecoverable spins with any use of the flight or engine power controls either at the entry into or during the spin; and
(iv) For the flaps-extended condition, the flaps may be retracted during the recovery but not before rotation has ceased.
(2) At the applicant's option, the airplane may be demonstrated to be spin resistant by the following:
(i) During the stall maneuver contained in §23.201, the pitch control must be pulled back and held against the stop. Then, using ailerons and rudders in the proper direction, it must be possible to maintain wings-level flight within 15 degrees of bank and to roll the airplane from a 30 degree bank in one direction to a 30 degree bank in the other direction;
(ii) Reduce the airplane speed using pitch control at a rate of approximately one knot per second until the pitch control reaches the stop; then, with the pitch control pulled back and held against the stop, apply full rudder control in a manner to promote spin entry for a period of seven seconds or through a 360 degree heading change, whichever occurs first. If the 360 degree heading change is reached first, it must have taken no fewer than four seconds. This maneuver must be performed first with the ailerons in the neutral position, and then with the ailerons deflected opposite the direction of turn in the most adverse manner. Power and airplane configuration must be set in accordance with §23.201(e) without change during the maneuver. At the end of seven seconds or a 360 degree heading change, the airplane must respond immediately and normally to primary flight controls applied to regain coordinated, unstalled flight without reversal of control effect and without exceeding the temporary control forces specified by §23.143(c); and
(iii) Compliance with §§23.201 and 23.203 must be demonstrated with the airplane in uncoordinated flight, corresponding to one ball width displacement on a slip-skid indicator, unless one ball width displacement cannot be obtained with full rudder, in which case the demonstration must be with full rudder applied.
(b) Utility category airplanes. A utility category airplane must meet the requirements of paragraph (a) of this section. In addition, the requirements of paragraph (c) of this section and §23.807(b)(7) must be met if approval for spinning is requested.
(c) Acrobatic category airplanes. An acrobatic category airplane must meet the spin requirements of paragraph (a) of this section and §23.807(b)(6). In addition, the following requirements must be met in each configuration for which approval for spinning is requested:
(1) The airplane must recover from any point in a spin up to and including six turns, or any greater number of turns for which certification is requested, in not more than one and one-half additional turns after initiation of the first control action for recovery. However, beyond three turns, the spin may be discontinued if spiral characteristics appear.
(2) The applicable airspeed limits and limit maneuvering load factors must not be exceeded. For flaps-extended configurations for which approval is requested, the flaps must not be retracted during the recovery.
(3) It must be impossible to obtain unrecoverable spins with any use of the flight or engine power controls either at the entry into or during the spin.
(4) There must be no characteristics during the spin (such as excessive rates of rotation or extreme oscillatory motion) that might prevent a successful recovery due to disorientation or incapacitation of the pilot.

Another good read is the Aircraft Certification Service - FAA Flight Test Responsibilities, Procedures, and Training which states:

506. Spin Tests. Spin tests conducted by FAA FTPs should be flown initially with a spin chute (or equivalent equipment) installed on the aircraft and approved by an FAA structural and/or systems engineer. (See Appendix 3 for additional guidance on requirements for spin recovery devices). After all spin modes have been evaluated and found satisfactory, the spin characteristics should be checked with the external spin chute removed, unless it is determined
that the spin chute installation has no significant effect on spin characteristics.

(Emphasis Mine)


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What are the differences between a GPS coupled autopilot and a GPSS autopilot?
I'm trying to understand the differences here between an autopilot that is "coupled" into a GPS/NavCom like a Garmin 530W and what GPSS and altitude hold (like in an S-TEC 50 autopilot) have to do with this. Can anyone explain this to me? Maybe there is no difference, I really need this explained.

GPS units paired with older autopilots such as the S-TEC 30/50 mentioned here do not automatically give GPSS steering to the autopilot unless the GPS has a GPSS system built in. In this case the additional GPSS unit swaps between traditional NAV/APR/BC modes that seek using deflection from the CDI and GPSS steering which is data-driven straight from the GPS. It is possible to get a PFD that has GPSS built in as well (Aspen Evolution) and takes care of this functionality.
A functional difference between these two systems is demonstrated as such with a Garmin GNS-530W/430W and an STEC-50 autopilot with the separate GPSS unit:
1) with the GPS giving guidance and GPSS off (or not installed) the autopilot treats the GPS input signal as a CDI input - in other words, if there is a course change of greater than 10 degrees in either direction the autopilot will follow no guidance and do whatever it wants to, for example ignoring a 90 degree right turn in the flight plan (other than making an initial heading change of a few degrees while attempting to track as the CDI quickly goes full deflection) and then continuing on in whatever random way it wants without following guidance or a flag showing on the CDI (there is no flag because the guidance is present, but it's out of range just like a VOR signal would be!). Accordingly all major course changes must be executed manually or in heading mode by hand then the autopilot is engaged in NAV mode to track the course once it is captured and within 10 degrees of the present course.
2) with the GPS giving guidance and GPSS on the GPSS unit sends direct roll steering commands to the autopilot that are extremely accurate. The autopilot must always be in HDG mode to accept these inputs. The heading bug on the DG or HSI is effectively ignored while GPSS is engaged. Here's an example: while tracking a course (or really at any point in flight), selection of a 90 degree right turn (say, direct to) in the GPS will result in direct roll steering commands being given to the autopilot and the autopilot executing those commands and following them extremely closely within the parameters of the autopilot design (standard rate turn, etc.), resulting in an automatic turn to the new course, including automatic intercept of that course if the GPS performs that function, and any following courses and changes being flown precisely and automatically as they are sequenced in the flight plan.

Source: I now own an aircraft that has this system and operate it all the time.

Pugz provided some very good information back on September 29th.  As I recently installed a Garmin GTN 650 and add S-TEC GPSS to my 35 year old S-TEC 60-2 autopilot I thought I might respond also.  As I did this installation myself I am quite familiar with the wiring involved which helps in understanding how the autopilot responds so differently to GPSS (GPS Roll Steering) than it does to the CDI (Course Deviation Indicator).  First we need to understand that after installing GPSS the autopilot has two completely different interfaces.  When in NAV mode the autopilot responds to the CDI for lateral guidance (and the CDI glide slope if the autopilot has that capability like my 60-2 does.)  When in HDG mode the autopilot would normally respond to the Heading Bug on the Directional Gyro but if GPSS is installed the autopilot actually has two separate functions while in HDG mode:  1) Follow the HDG bug on the DG; 2) Follow the GPS Roll Steering commands that are provided by the GPS via ARINC 429 output that is routed to the autopilot GPSS module and converted into Heading Commands as if the HDG bug were providing them.  In order to implement this the GPSS module has a switch to change from HDG mode to GPSS mode.  As far as the autopilot is concerned he is just getting heading commands from a HDG bug on the directional gyro.  The autopilot has no idea that he is being driven buy the GPS while in GPSS mode.  Just imagine that a very skilled pilot is operating the HGD bug on the DG and the pilot knows exactly when and how much heading change to make in order to turn smoothly on the next route segment or intercept that route segment if off course. This is exactly what is happening except that the very skilled pilot happens to be the GPS receiver.  The GPS knows exactly what heading changes need to be made and when to make them in order to guide the aircraft around a procedure turn and intercept the final approach course.
The new Garmin GI-106B CDI that I installed along with the GTN 650 still has some very important functions.  After the GPS has guided the autopilot (via GPSS) through the entire route and possibly a procedure turn course reversal and intercepted the final approach course I switch the autopilot from HDG mode to NAV mode in order to engage the autopilot on the CDI.  Now if I am flying an ILS or RNAV LPV approach the autopilot has both vertical and lateral guidance via the CDI.  The CDI will either be getting input from the ILS signal or from the GPS depending on what has has been selected on the GTN 650.  Both autopilot interfaces are still important (HDG/GPSS & CDI) but the autopilot CDI interface is used only for the final approach where vertical guidance is needed.  Most of flight is best flown with the autopilot engaged in HDG mode either flying on the actual heading bug (being vectored) or with GPSS engaged and the GPS is turning the virtual heading bug for you in order to fly the programmed route.

Spot on. Also note that altitude/VS modes other than NAV/APR glideslope capture use the S-TEC’s built in pressure sensor rather than GPS VNAV or other instruments.

An autopilot in NAV mode, using GPS as a source (GN*430+), will do the same thing as an autopilot using GPSS directly from a GPS (for example, KLN89/90 or GPS155XL).
GPSS is, as I understand it, a holdover from the time when panel-mount IFR-approved GPS units were standalone. GPSS was the way to feed your autopilot course correction data from that dedicated device. When the Garmin GNS430 hit the market and utterly destroyed the competition, GPS/NAV/COM became the standard, and the GPS or CDI control determined what the data was going to the autopilot.
In some aircraft you get into odd situations where a newer panel is paired with an older autopilot. I have a fair bit of time in an AG-5B Tiger with G1000, and it has the S-Tec System 30 autopilot with a GPSS module. I never understood this setup, as the System 30 has low/high VOR/LOC/GPS tracking built in. The GPSS module was completely redundant and seemed to be a holdover from the pre-G1000 model of the aircraft.

Source: personal experience, made more certain via this thread on the Avidyne forums

Nice, I'm talking about an AG-5B Tiger too. Where did you get that time at?

Ha, man, I'm only 18 months late. I was working with an owner's on his instrument rating.